The disclosure of the following priority application is herein incorporated by reference: Japanese Patent Application No. 2001-021123, filed Jan. 30, 2001.
1. Field of the Invention
The present invention relates to a device and to a camera accessory which are mounted upon an accessory shoe which is provided to a main device.
2. Description of the Related Art
There is a per se known type of flash device which is fitted during use to a hot shoe of a camera, such as, for example, the one disclosed in Japanese Laid Open Patent Publication No. H9-43683. With this flash device, a lock nut is disposed upon a leg portion of the flash device. And, with the leg portion inserted into the hot shoe, a specially provided lock pin is projected from the leg portion by rotating the lock nut, and this lock pin engages into a pin hole which is specially provided in the hot shoe.
However, with this type of prior art flash device, it is necessary to form a pin hole in the hot shoe in a position which corresponds to the lock pin in the leg portion of the flash device in order to fix the flash device to the hot shoe of the camera, and the problem arises that it is difficult to fix the flash device to a conventional camera in the hot shoe of which no such pin hole is provided.
Furthermore, with another prior art which is disclosed in Japanese Laid Open Patent Publication No. S62-123435, a method is proposed of not providing any dedicated lock pin or lock hole, but instead fixing the flash device to the hot shoe of the camera by pressing it against the external upper surface thereof and thereby engaging it thereto by friction; but in this case it is not possible to anticipate any secure and strong fixing action, since there is a danger that this external surface of the camera may be damaged or dirty.
Accordingly, it is the objective of the present invention to provide a device which can be fixed easily and securely to an accessory shoe which is provided to a main device. In particular, it is the objective of the present invention to provide a camera accessory such as a flash device or the like, which can be fixed easily and securely to an accessory shoe of a camera.
In order to attain the above objective, a device according to the present invention that is to be fitted to an accessory shoe provided to a main device, comprises: an insertion portion that is inserted into the accessory shoe; a shift member; an actuation member; and a shift device that shifts the shift member according to actuation of the actuation member, and the shift device: presses a portion of the shift member against an inner wall surface of the accessory shoe according to actuation of the actuation member, when the insertion portion is fixed after insertion in the accessory shoe; and releases this pressing of the portion of the shift member against the inner wall surface of the accessory shoe according to actuation of the actuation member in order to remove the insertion portion from the accessory shoe.
In this device, it is preferred that: the actuation member is provided so as to be rotatable; and the shift device comprises a biasing member that biases the shift member towards the accessory shoe, and an actuation shaft that is linked to and is rotated by the actuation member and has a displacement portion; and, due to shifting of the displacement portion according to rotation of the actuation shaft, shifts the shift member away from the accessory shoe to press the portion of the shift member against an upper inner wall surface of the accessory shoe. In this case, it is preferred that the shift device further comprises a support member to which a tip portion of the actuation shaft is engaged and which is contacted to an upper surface of the insertion portion.
Also, it is preferred that: the actuation member is provided so as to be rotatable; and the shift device comprises a biasing member that biases the shift member away from the accessory shoe, and an actuation shaft that is linked to and is rotated by the actuation member and has a displacement portion, and, due to shifting of the displacement portion according to rotation of the actuation shaft, shifts the shift member towards the accessory shoe to press the portion of the shift member against a lower inner wall surface of the accessory shoe.
Also, it is preferred that the portion of the shift member comprises a projecting portion that contacts an inner wall surface of the accessory shoe when being pressed.
Also, it is preferred that: the shift member comprises a first shift member and a second shift member; the actuation member is provided so as to be rotatable; and the shift device comprises a first biasing member that biases the first shift member towards the accessory shoe, a second biasing member that biases the second shift member away from the accessory shoe, and an actuation shaft that is linked to and is rotated by the actuation member and has a displacement portion, and the shift device, due to shifting of the displacement portion according to rotation of the actuation shaft, shifts the first shift member away from the accessory shoe to press a portion of the first shift member against an upper inner wall surface of the accessory shoe, and shifts the second shift member towards the accessory shoe to press a portion of the second shift member against a lower inner wall surface of the accessory shoe. In this case, it is preferred that the shift device further comprises a support member to which a tip portion of the actuation shaft is engaged and which is contacted to an upper surface of the insertion portion.
A camera accessory according to the present invention that is to be fitted to an accessory shoe provided to a camera, comprises: an insertion portion that is inserted into the accessory shoe; a shift member; an actuation member; and a shift device that shifts the shift member upon actuation of the actuation member, and the shift device: presses a portion of the shift member against an inner wall surface of the accessory shoe according to actuation of the actuation member, when the insertion portion is fixed after insertion in the accessory shoe; and releases this pressing of the portion of the shift member against the inner wall surface of the accessory shoe according to actuation of the actuation member in order to remove the insertion portion from the accessory shoe. In this case, it is preferred that the camera accessory is a flash device. Furthermore, it is preferred that the shift member is formed from a metallic material that is electrically conductive, and a standard potential line is connected to the shift member.